Field of the Invention
This invention relates to lighting and display technologies, and in particular, it relates to a light source system and related projection system.
Description of the Related Art
In conventional single-plate digital micromirror device (DMD) system, multiple primary lights sequentially and alternatingly enters the DMD to be modulated. The modulated single-color images rapidly switch on the screen, so that a color image is perceived by the viewer due to mixing of the sequential single-color images by the effect of persistence of vision of the human eyes. In conventional technologies, typically red (R), green (G) and blue (B) primary color lights are used for modulation. A commonly used method of generating a three primary color light sequence is to use an excitation light to excite different segments of a color wheel sequentially to generate different color lights sequentially. In such a structure, the excitation light may employ a blue LED (light emitting diode) or blue laser. The color wheel has three segments, one of which being a light transmitting segment which transmits the blue light, while the other two carry green and red phosphors, respectively, to absorb the excitation light and generate green and red converted lights, respectively.
However, in such a light source device that uses phosphors, red phosphor is a bottleneck that limits that working life and light emission efficiency of the light source device. The wavelength conversion efficiency of red phosphor tends to be relatively low; the energy not converted to red light becomes heat, which quickly raises the temperature of the phosphor, which in turn adversely affects its light emitting efficiency and life, causing a vicious cycle.